Area Required to Meet Global Needs

Here I discuss the collection area requirements to meet global energy needs, but before that, smaller municipal applications will be discussed. Municipal solar power plants of the size range of 2 to 10 mW require 10 to 50 acres of 

Post-Oil Energy Technology After the Age of Fossil Fuels 

Therefore, to collect the 750 Q that is expected to be the global energy consumption by 2050 would require 488 x 750 = 366,000 km2, which is 4% of the area of the Sahara (9 million km2). Therefore, the solar radiation reaching less than 4% of the Sahara would suffice to provide all the energy required by mankind in 2050. Another way to express the abundance of solar energy is to note that the total area of high insolation on the planet is more than 5,000 

Considering that the electricity used by the United States is about 4.5 x 1012 kWh/yr (15.35Q), if this amount of energy was to be produced by solar farms in the arid southwestern regions (the area of the Mojave Desert alone is 15,000 mi2), the area required to generate 1 Q at a yearly insolation is 2,250 kWh/m2/yr and with a collector efficiency of 20% is 2,250/3,000 x 488 x 15.35 = 5,618 km2 or 2,194 mi2. Therefore, 14.6% of the Mojave Desert would need to be covered to meet the total electric energy requirement of the United States. 

In the Southwest region of the United States, the area requirements of smaller photovoltaic systems can be estimated at about 6 acres per mW or about 300 acres for a smaller city requiring 50 mW. In the same geographic location, if part of the roof area is covered with collectors and is connected to the grid, the system usually can make the home energy free, including transportation by charging the batteries of an electric car with the excess electricity. 

---